My question is, will Banshee keep his Irish history? So far the X-men movies haven't been quite well with characters keeping their backgrounds or accents, and I'd dislike seeing Banshee show up speaking American.

Michael Fassbender (Irish/German actor cast young Magneto) will surely have to change his own accent to play Magneto, but an Irish character like Banshee won't show up sounding Texan, will he?

Eh, I'm not getting my hopes up that they'll keep his origin. The lad they got to play Colossus claims he even auditioned in Russian, but was told not to worry about it. Probably because he only has a quote or two. But still, I've grown up with these characters, and hate seeing them stripped off their roots.

Maybe that's just me though.

I think that he will. If they went through the trouble to find an actor with Banshee's look, then I'm pretty sure that they'll follow through the rest of the way. It'd seem pointless to fulfill only some of the characterization requirements.